[PATCH 4.19 002/220] i2c: mediatek: modify threshold passed to i2c_get_dma_safe_msg_buf()

Greg Kroah-Hartman
2019-11-22T10:56:22Z

From: Hsin-Yi Wang <hsinyi@chromium.org>

commit bc1a7f75c85e226e82f183d30d75c357f92b6029 upstream.

DMA with zero-length transfers doesn't make sense and this HW doesn't
support them at all, so increase the threshold.

Fixes: fc66b39fe36a ("i2c: mediatek: Use DMA safe buffers for i2c transactions")
Signed-off-by: Hsin-Yi Wang <hsinyi@chromium.org>
[wsa: reworded commit message]
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Cc: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
drivers/i2c/busses/i2c-mt65xx.c | 8 ++++----
1 file changed, 4 insertions(+), 4 deletions(-)

--- a/drivers/i2c/busses/i2c-mt65xx.c
+++ b/drivers/i2c/busses/i2c-mt65xx.c
@@ -503,7 +503,7 @@ static int mtk_i2c_do_transfer(struct mt
writel(I2C_DMA_INT_FLAG_NONE, i2c->pdmabase + OFFSET_INT_FLAG);
writel(I2C_DMA_CON_RX, i2c->pdmabase + OFFSET_CON);

- dma_rd_buf = i2c_get_dma_safe_msg_buf(msgs, 0);
+ dma_rd_buf = i2c_get_dma_safe_msg_buf(msgs, 1);
if (!dma_rd_buf)
return -ENOMEM;

@@ -526,7 +526,7 @@ static int mtk_i2c_do_transfer(struct mt
writel(I2C_DMA_INT_FLAG_NONE, i2c->pdmabase + OFFSET_INT_FLAG);
writel(I2C_DMA_CON_TX, i2c->pdmabase + OFFSET_CON);

- dma_wr_buf = i2c_get_dma_safe_msg_buf(msgs, 0);
+ dma_wr_buf = i2c_get_dma_safe_msg_buf(msgs, 1);
if (!dma_wr_buf)
return -ENOMEM;

@@ -549,7 +549,7 @@ static int mtk_i2c_do_transfer(struct mt
writel(I2C_DMA_CLR_FLAG, i2c->pdmabase + OFFSET_INT_FLAG);
writel(I2C_DMA_CLR_FLAG, i2c->pdmabase + OFFSET_CON);

- dma_wr_buf = i2c_get_dma_safe_msg_buf(msgs, 0);
+ dma_wr_buf = i2c_get_dma_safe_msg_buf(msgs, 1);
if (!dma_wr_buf)
return -ENOMEM;

@@ -561,7 +561,7 @@ static int mtk_i2c_do_transfer(struct mt
return -ENOMEM;
}

- dma_rd_buf = i2c_get_dma_safe_msg_buf((msgs + 1), 0);
+ dma_rd_buf = i2c_get_dma_safe_msg_buf((msgs + 1), 1);
if (!dma_rd_buf) {
dma_unmap_single(i2c->dev, wpaddr,
msgs->len, DMA_TO_DEVICE);